Documents bound with helical coil (usually called spiral coil) can open flat on a desk or table and offer 360 degree rotation for easy note taking. This binding style is durable and is often used for documents that need to be mailed. Spiral coil binding spines are also available in more colors and sizes than other binding styles.
One of the strengths of spiral coil binding is that the supplies are available in a variety of lengths. Most users purchase spiral coils in twelve inch lengths. This spine is inserted onto an eleven-inch document and the excess length of coil is cut and crimped at each end of the book. However, the forming process for creating spiral coil binding elements allows them to be created in virtually any length. Spiral coils are sometimes made from low-carbon steel. Spiral coil binding supplies are also available in a wide variety of colors.